This project would establish a centralized source of agents for use in preclinical and clinical studies by the chemoprevention program of the National Cancer Institute (NCI). For preclinical studies, the project would provide: purchase of bulk reagent chemical substances; receipt of agents from suppliers; safe and stable storage; repacking agents to meet user needs; and shipment of agents to users with appropriate characterization data and handling instructions. For suppliers; safe and stable storage; administrative support as needed for dosage formulation, encapsulation, calendar packing and labeling, including shipment to NCI designated contractors to accomplish these tasks if necessary; and shipment to final destination. Essential activities for the overall operation include: monitoring stock levels at user locations; inventory control to ensure timely reordering, and shipping of agents; maintenance of up-to-date records of shipments; and limited quality assurance capability such as shelf life and purity of bulk agents.